The Data Management, Statistics, and Recruitment Core will be based in the Epidemiology Data Center of the Graduate School of Public Health. The responsibilities of the Core will be to provide statistical expertise, perform data management activities and accomplish patient recruitment. The project leaders will still assume the responsibility for the scientific direction of their project analyses, but the Core will provide resources tp edit data in preparation for analysis and assist with the execution of the analysis. The Core will ensure the availability of appropriate statistical expertise for the scientific questions addressed in the Program Project and the diverse types of data to be collected and analyzed by the individual projects. In addition, Core C will be responsible for patient recruitment, drawing on the considerable expertise and experience of the Department of Epidemiology. In the past submission, investigators from the Carnegie Mellon Department of Statistics were used as consultants for specialized statistical applications that could not be handled by the Epidemiology Data Center. While this arrangement will remain on an informal basis, such consultation will now be primarily provided by the Faculty of the Epidemiology Data Center.